Will there be any additional Imager books after Endgames?

It’s highly unlikely, but I won’t absolutely foreclose the possibility. At this point, I’ve written five fantasy series and three science fiction “series” (linked books in different futures), and I still am writing, with three more Recluce books and at least one more, and possibly two Grand Illusion books coming out in the next three years. While I intend to keep writing, I’m not exactly a spring chicken, as the old saying goes, and we’ll just have to see.